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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Environmental science & technology 13 (1979), S. 446-451 
    ISSN: 1520-5851
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 15 (1983), S. 1321-1328 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aqueous bromine reacts with alkyl-sidechain amino acids through a series of steps resulting in the formation of the corresponding alkyl aldelydes and nitriles. The kinetics and the mechanism of the interaction of bromine with alanine are examined. The products and the rates of this reaction are dependent in a complex way on the initial reactant concentration and pH. Acetaldeyde production is favored at low bromine-to-alanine ratios, low bromine concentrations, and pH values above 6. The first-order rate constant for the formation of acetaldelyde from alanine under these conditions is k4 = 1.98 × 1015 e-22,500/RT min-1. At higher concentration the nitrile is formed through a bromoimine intermediate. Under most conditions the nitrile appears to form from a catalyzed decomposition of the bromoimine which is too fast to be followed by the methods used in this study. However, residual amounts of the bromoimine decay by a slower first-order mechanism. The rate constant for this slower reaction in the case of alanine at pH 6.8-6.9 and alanine concentrations of 1 × 10-4M is k6 = 1.75 × 105 e-10,400/RT min-1.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 16 (1984), S. 251-258 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of the reaction of aqueous sulfite with the N-chloropeptide N-chloroalanylalanylalanine has been studied as a function of pH, temperature, and ionic strength. The results of this work suggest that the mechanism of the reaction involves the interaction of the neutral chloramine with the three ionic forms of sulfite, SO3-2, HSO3-, and H2SO3, with the rate of reaction increasing rapidly with increasing protonation. The estimated second-order rate constants for each ionic species as a function of temperature are \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm H}_{\rm 2} {\rm SO}_{\rm 3} } \hfill & {k_1 \, = \,2.00\, \times \,10^8 \,{\rm exp}\left( {{{ - 1544} \mathord{\left/ {\vphantom {{ - 1544} {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right){\rm min}^{ - 1} } \hfill \\ {{\rm HSO}_{\rm 3}^ - } \hfill & {k_2 \, = \,4.35\, \times \,10^4 \,{\rm exp}\left( {{{ - 1170} \mathord{\left/ {\vphantom {{ - 1170} {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right){\rm min}^{ - 1} } \hfill \\ {\,\,{\rm SO}_{\rm 3}^{ - 2} } \hfill & {k_3 \, = 1.58\, \times \,10^{12} \,{\rm exp}\left( {{{ - 12,660} \mathord{\left/ {\vphantom {{ - 12,660} {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right){\rm min}^{ - 1} } \hfill \\ \end{array} $$\end{document} where the activation energies are in units of cal/mol.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 401-411 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The tripeptide alanylalanylalanine reacts with either HOCl or HOBr to form a N,N-dihalopeptide. These compounds decompose to the N-halo-N′-(α-iminoketo)peptides plus halide ion. The rate constants for these reactions in 0.4-M NaCl were determined to be \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{l} \begin{array}{*{20}c}{{\rm Cl:}} \hfill & {k_4 = 1.52 \times 10^{15} e^{ - 19,600/RT} \,{\rm min}^{{\rm - 1}} \,({\rm pH}\,{\rm 6}{\rm .7)}} \hfill \\\end{array} \\ \begin{array}{*{20}c}{{\rm Br:}} \hfill & {k_4 = 1.06 \times 10^{15} e^{ - 18,400/RT} \,{\rm min}^{{\rm - 1}} \,({\rm pH}\,{\rm 6}{\rm .6)}} \hfill \\\end{array} \\ \end{array} $$\end{document} where the activation energies are in cal/mol. The N-halo-N′-(α-iminoketo)-peptides slowly decompose either by a two-step hydrolysis reaction to form ammonia, halide ion, and an N-(α-acylketo)peptide, or by direct decomposition to a nitrile, an isocyanopeptide, and a halide ion.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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